Win32: ERROR_DIRECTORY should map to ENOTDIR

Imported from http://bugzilla.roxen.com/bugzilla/show_bug.cgi?id=7271

Reported by Martin Karlgren marty@roxen.com

The win32 ERROR_DIRECTORY (267) code should arguably map to ENOTDIR. _dosmaperr doesn't seem to care about ERROR_DIRECTORY for some reason, but it seems like a logical thing to do.

As an example, python does a corresponding remap since a couple of years, see http://bugs.python.org/issue12802

A remap could easily be performed in set_errno_from_win32_error.